Key cutting machine

ABSTRACT

A key cutting machine as disclosed which is semi-automatic operation in that the master key to be copied and a blank key are mounted in vises, a door is closed, the machine is turned on and it automatically cuts a key blank in accordance with the master key, brushes the key to remove any burr and then the machine shuts itself off. The door may then be opened and the keys removed from the vises.

United States Patent 1151 3, 75, Hungerford, Jr. et a]. 1 1 July 11, 1972 1 KEY CUTTING MACHINE 2,809,566 10/1957 Orchard ..90/13.0s

[72] Inventors: Philip C. l-lungerlord. Jr., Cleveland; John I I I L. Gereby, Wickliffe; Robert 11. Richens, Pnma'v'immmfl-ollweldenfeld Bedf d HeightsI n f Ohio Anorney-Woodling, Krost, Granger and Rust [73] Asslgnee: Cole National Corporation I 57] ABSTRACT 22 F1 d: N 27,197 C I 0v 0 A key cumng machlne as dlsclosed whlch 1s seml-automauc [2 [1 Appl. No.: 93,145 operation in that the master key to be copied and a blank key are mounted in Vises, a door is closed, the machine is turned 1521 0.5. CI ..90/13.0s and "mmafically cuts a key blank acm'dance [SI 1 In. CI. 1 v v o o .3231: [H6 the master Y- brushes the y to remove y and 581 Field 01 Search 90/1105; 83/4 1 3; 76/] 10 the machine shuts itself ofii The door y then be opened and the keys removed from the visesv [56] References Cited 23 Claims, 9 Drawing figures UNITED STATES PATENTS 1138,999 6/l964 Haggstrom ..90/l 3.05

I I I l l/ l 1 I I I I CII T -I;'"' o 1Q. 22 I I I o o 77 I6 76 /7 6.9 I I 1:: 3/ 30 I 1 28 l "i114 d C; r L? PHEN'TEDJUL 1 1 m2 SHEET 2 OF 6 SHEET 3 OF 6 5 M N M b m 6. 11/14 WMN a 4/, R L .o r f r ju nk A Han/ PATENTEDJUL 11 I972 3.675.536

SHEET 5 or 6 A ORA/E YS PKTENTEHJUL 1 1 I972 SHEET 5 UP 6 29 MOTOR J GEAR REDUCTION FIG: .9

KEY CUTTING MACHINE BACKGROUND OF THE INVENTION Many different forms of key cutting machines have been produced but many have required the presence of a skilled operator in order to produce satisfactory keys. Current retailing practices have dictated a reduction in the number of personnel in a retail establishment because of the increasingly higher labor rates and this has encouraged the discount or supermarket type of operation wherein the customer selects his own merchandise without help of a retail store clerk and then merely pays for this merchandise at a check-out counter. What retail store clerks remain are quite busy and cannot spend the time to operate a complicated key machine nor can the management spare the time to adequately train all their personnel. The result is that many of the personnel attempting to operate the key machine for a customer are inadequately trained or in a hurry and many key blanks are spoiled trying to duplicate the customer's master key.

Additionally, many prior art key cutting machines were not particularly safe in operation because of the exposed moving parts and especially the moving cutter wheel and if unskilled or semi-skilled personnel were attempting to operate the keying cutting machine, this could result in a considerable hazard with possibly subjecting the management to damage litigation.

Additionally, many prior art machines were rather lightly constructed so that the machine could easily get out of adjustment due to wear or mis-alignment of the parts and this again tool skilled personnel to keep the machine in adjustment for cutting a proper key.

In several prior art machines there was a single drive means to provide the relative longitudinal reciprocation between the cutter and the key and this was often a positive drive which, if the mechanism were to jam because of a dull cutter or other means, then the mechanism could be damaged unless the operating personnel were very prompt in turning off the machine. In others, metal chips flying from the key cutter might endanger the personnel standing near the machine or the rotating cutter could endanger the fingers of inexperienced personnel.

Accordingly, an object of the invention is to provide a key cutting machine with obviates the above-mentioned disadvantages.

Another object of the invention is to provide a key cutting machine with an impositive or yielding drive in the cutting direction and a positive drive in the return direction.

Another object of the invention is to provide a key cutting machine with a door closable to protect nearby personnel during the cutting operation.

Another object of the invention is to provide a key cutting machine with a door operated switch to turn off the cutter should the door he opened.

Another object of the invention is to provide a key cutting machine with a cam and follower operated longitudinal drive mechanism for the carriage with spring urging on the cam follower to provide a yielding drive of the carriage in case the carriage movement should be impeded.

Another object of the invention is to provide a key cutting machine with a reciprocating brush to break off any burr on the cut key.

Another object of the invention is to provide a key cutting machine wherein burr brushing means is selectively operable only on the return motion of a key cutting carriage but not on the key cutting motion.

SUMMARY OF THE INVENTION The invention may be incorporated in a key cutting machine, comprising, in combination, a base, a master key vise, a blank key vise, a stylus to cooperate with a master key in the master key vise, a key cutter to cut a blank key in the blank key vise, a carriage movable on said base, means including said carriage establishing relative longitudinal and lateral movement between said key cutter and blank key vise in accordance with relative longitudinal and lateral movement, respectively, between said stylus and master key vise, motor means, first yielding drive means from said motor means to said carriage for said relative longitudinal movement in a first direction, and second positive drive means from said motor means to said carriage for said relative longitudinal movement in the opposite direction.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a front elevational view of a key cutting machine embodying the invention;

FIG. 2 is a left side elevation of the machine of FIG. 1',

FIG. 3 is a plan view of the machine of FIG. 1;

FIG. 4 is a left side elevation similar to FIG. 2 but with the door in the open position;

FIG. 5 is an enlarged partial view of the key brushing mechanism;

FIG. 6 is a view similar to FIG. 5 but with the brush in an extended position;

FIG. 7 is an enlarged sectional view on line 77 of FIG. 2 and showing the front view of a cam and follower;

FIG. 8 is a top view of FIG. 7; and

FIG. 9 is an end view of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT The figures of the drawing show a key cutting machine I] designed to use a master key 12 as a pattern for cutting a key blank 13 in conformity therewith. The machine ll includes a base 14 on which the parts are mounted and in this machine there is provided a master key vise l6 and a blank key vise 17 for holding the master key 12 and key blank 13, respectively. A stylus I8 is provided to cooperate with and feel the contours of the master key 12 and a key cutter, shown as a rotating type key cutter 19, is provided to cooperate with and cut contours on the blank key 13. A carriage 21 is provided on the machine II with this carriage being movable on the base 14. Means is provided including this carriage 21 to establish relative longitudinal and lateral movement between the key cutter l9 and the blank key 13in accordance with relative longitudinal and lateral movement, respectively, between the stylus l8 and the master key 12. The carriage 21 is pivotally mounted on a carriage shaft 22 and this pivotal movement of the carriage 2] establishes the aforementioned relative lateral movement because the stylus l8 and the cutter 19 are mounted on the carriage 21. The key vises l6 and 17 are mounted fixedly on the base 14. Accordingly, the aforementioned relative longitudinal movement is provided by longitudinal movement of the carriage 21 along this carriage shaft 22. This provides movement of the key cutter 19 in accordance with longitudinal movement of the stylus 18.

The vises l6 and 17 may be actuated in any suitable manner and as shown in the drawing the vises are actuable by manual handle 23 to clamp the keys in the respective vises. In FIG. 2 the clamp handle 23 is shown in the clamped position.

The carriage 21 carries a cutter shalt 26 journalled for rotation therein parallel to the carriage shaft 22. The rotatable key cutter 19 is directly fixed to this cutter shaft 26 for rotation therewith as is a belt pulley 27. A cutter motor 28 is fixedly mounted on the rear of the base 14 and has a shaft 30 parallel to the carriage shaft 22. This shaft 30 has a belt pulley 31 and a belt 32 interconnects the pulleys 27 and 31 to drive the cutter shaft 26.

A drive motor 29 driving through gear reduction mechanism 35 is provided for establishing motive means for reciprocating the carriage 21. This motor 29 and gear reduction mechanism 35 are mounted on the rear of the carriage 2 l to help counterbalance the carriage so that only a small force of about one pound is applied on the stylus l8 bearing against the master key 12. This same force will be present on the cutter 19 against the blank key 13.

IOIMA mna A first and a second drive means is provided from the motor 29 to the carriage 21. The first drive means is a yielding drive means and the second drive means is a positive drive means. The gear reduction mechanism 35 rotates a cam 36, better shown in FIGS. 7 and 8. This cam 36 cooperates with first and second cam followers 37 and 38, respectively. Springs 39 engage these cam followers 37 and 38 and urge the cam followers into generally diametrically opposed contact with the cam 36. Both cam followers 37 and 38 have a longitudinal aperture 40 received on the carriage shaft 22 to be pivotable thereon and to pivot with movements of the carriage 21. The cam follower 38 is held by snap rings 41 in a fixed longitudinal position on the carriage shaft 22 whereas cam follower 37 may longitudinally move on the carriage shaft 22 as yieldingly urged against the cam 36 by the springs 39 and dependent upon the particular diametral dimension of the cam 36 for that rotational position of the cam. It is the springs 39 which provide the first yielding drive means for reciprocating the carriage 21 in a first longitudinal direction. The longitudinally fixed position of the cam follower 38 is that which establishes the second positive drive means for the carriage in the opposite longitudinal direction.

FIG. 7 illustrates the position of the cam 36 before the cutting of the key blank 13 by movement of the carriage 21 to the left as viewed in FIG. 1. As the motor 29 rotates the cam 36 through the gear reduction mechanism 35, this cam 36 rotates clockwise, as seen in FIG. 7. This tends to move the cam follower 37 to the right which is resisted by the urging of the springs 39. The result is that the carriage 21, on which the cam 36 is rotatably mounted, is moved to the left so that the cam 36 always tends to remain in engagement with the cam follower 38. This engagement is continuous unless some unexpected large force must be overcome. An example of this might be an improper mounting of the master key 12 in the master key vise 16 so that the stylus 18 engaged some right angle shoulder. Another example might be an exceptionally dull cutter 19 such that the cutter 19 ran up against a substantially right angle shoulder which it was unable to cut and this would develop a large force restraining the longitudinal movement of the carriage 21 in the first or leftward movement thereof. Assuming that the normal forces are encountered, the springs 39 will establish a yielding first drive means to longitudinally reciprocate the carriage 21 to the lefi in a key cutting direction. The radial dimension of the cam 36 between the high and low points thereon is sufficient to provide a key cutting travel of the carriage 21. When the low point on the cam 36 engages the cam follower 38, this terminates the first yielding drive means and the second positive drive means commences which will reciprocate the carriage 21 back to the right in a return non-cutting direction. The reason this is a positive drive means is that the cam 36 will be co-acting with the longitudinally immovable cam follower 38, with the cam rotating toward the high point on the cam and this will positively drive the carriage 21 toward the right, toward the position shown in FIG. 1. This may be termed the initial position at the start of the key cutting operation. FIG. 1 shows the belt 32 as being laterally shifted to the right on the cutter shaft 26 and the lateral flexing of the belt 32 permits this longitudinal movement of the carriage 21 while still providing rotative drive to the cutter 19.

A brush mechanism 45, better shown in FIGS. and 6, is provided to brush away any burr on the cut key 13. This brush mechanism 45 is provided, of course, only for the key blank 13, not the master key 12, and is designed to come into use only during the reciprocation of the carriage 21 to the right as viewed in FIG. 1. This will be during the time when the second positive drive means is actuating the carriage 21. FIG. 6 shows this brush mechanism 45 in the extended position whereat a brush 46 is in engagement with the cut key 13. The brush mechanism 45 includes generally a first arm 48 and a second arm 49 interconnected at a pivot 50. The first arm 49 is pivotally journalled on the carriage shaft 22 and connected for longitudinal reciprocation on the carriage shaft with the carriage 21. A tension spring 51 engages hooks on the arms 48 and 49 tending to urge these arms into a straight position shown in FIG. 6. This urges the brush 46 to the extended position as shown in this figure. An eccentric cam 53 is fixedly mounted on the cutter shaft 26 for rotation therewith and cooperates with a cam follower 54 fixed on the outer end of the second brush arm 49. The rotation of this eccentric 53 thus causes up and down arcuate movement about shaft 22 of the brush 46 transverse to and in engagement with the cut key 13 to break ofi' any burr on this cut key.

A longitudinal groove 56 is provided in the right end of the carriage shaft 22 and is shown in FIG. 3. This longitudinal groove has an exit ramp 57 merging smoothly with the circumference of the shaft 22 at a location remote from the right end of this shaft 22. The longitudinal groove 56 has a right angle shoulder 58 substantially along a radius from the axis of this shaft. An elastic finger 59 molded as a part of the journal bearing on the first brush arm 48 elastically engages this right angle shoulder 58 as best shown in FIG. 5. The finger 59 is elastically urged toward the axis of the shaft 22 by the natural resiliency of the material of the first brush arm 48. FIG. 2 shows a transparent door 61 in a closed position helping to cover the key cutting machine 11 and FIG. 4 shows this door 61 is in an open position. At such time the carriage 21 is raised to an inoperative position and FIG. 5 shows this first brush arm 48 as also raised with the carriage 21. Accordingly, the elastic finger 59 will enter the longitudinal groove 56 so that the end of the finger may engage the right angle shoulder 58. This cocks the brush mechanism 45. Upon subsequent lowering of the door 61 and lowering of the carriage 21, the lowering of the cutter shaft 26 then bends the brush arm 49 relative to the first brush arm 48 and stresses the tension spring 51. The brush mechanism 45 is then in the position shown in FIG. 5 where it is cocked, ready for use, but the brush 46 is to the rear out of engagement with the key blank 13. The brush mechanism 45 remains in this cocked out-of-the-way position during the first drive means which drives the carriage to the left as shown in FIG. 1. Just prior to the termination of the leftward movement of the carriage 21, the elastic finger 59 will move up the exit ramp 57 of the longitudinal groove 56 and when the end of the finger 59 no longer engages the right angle shoulder 58, there is nothing resisting the extension force of the spring 51. Accordingly, the brush mechanism 45 will be triggered and be extended to the position shown in FIG. 6. In this extended position the brush 46 engages the cut key 13. The cutter shaft 26 will be rotating at this time of driving the carriage 21 to the right as shown in FIG. 1, and accordingly the cam 53 will reciprocate the brush 46 up and down to debur any burr remaining on this cut key 13. Upon the completion of the cutting movement, when the door 61 is raised, this raises the carriage 21 to about a vertical position with the cutter shaft 26 nearly vertically above the carriage shaft 22. In this position the elastic finger 59 may again enter the longitudinal slot and the end of the finger will be adjacent the right angle shoulder 58. This recocks the brush mechanism ready for the next key cutting operation.

The key cutting machine 11 has a cover 62 to help protect the machine from dirt and also to protect personnel near the machine from being injured in die moving mechanism. The door 61 cooperates with the cover 62 to enclose the machine 11. As stated above the door 61 may be raised to an open position to amount and remove the keys 12 and 13. The door 61 is pivoted on a door pivot 63 and may be pivoted about 60 between a closed position shown in FIG. 2 to an open position shown in FIG. 4. A slot 64 is fastened on the inside of one side of the door 61 and cooperates with a pivot pin 65 fixedly carried on the outer end of a spring arm 66. This spring arm is pivotally journalled on the carriage shah 22 and carries a fixed pin 67 on the rear end thereof cooperating with some lost motion with a semi-circular groove 68 on the rear of the carriage 21. Accordingly, as the door is swung upwardly to an open position by being swung through an arc of about 60. the pin 65 also moves upwardly trough an arc of about 60and this swings the carriage 21 upwardly through an arc of about 55.

101044 UIOS 1t accordingly is in an inoperative position away from the keys 12 and 13 so that they may be removed and new keys placed in the vises 16 and 17. The arm 66 is a spring arm so that a service man may take hold of a handle 69 on the front end of this arm 66 and spring the pivot pin 65 out of the slot 64. This will permit how to lower the can'iage 21 into operative position even with the door 61 open so that necessary servicing of the machine may take place. A switch 72 is fixed on the base 14 and is controlled by the closing of the door 61. This switch is connected in circuit with the cutter motor 28 so that should the door 61 be opened during operation of the machine, this will de-energize the cutter motor 28 and stop rotation of the cutter 19. This is a safety factor. The drive motor 29 is not deenergized by actuation of this switch 72 and this is to make sure that the carriage 21 will complete its cycle of movement and return to the initial position as shown in FIG. 1.

When the carriage 21 is raised, the cutter shaft 26 comes closer to the motor shaft 30 than when in the lower position as shown in FIG. 2. Accordingly, in order to maintain tension on the belt 32 so that it will not slip off the pulleys 31 and 27, a pin 73 on the rear of the carriage 21 engages the inside of the lower run of the belt 32 to pull it downwardly as an idler and thus maintain sufficient tension on this belt to retain it on the two pulleys 27 and 31. This avoids having the belt 32 fall off the pulleys whenever the carriage 21 is raised.

When the carriage 21 is in the lower or operative position as shown in FIG. 2, then the axis of the cutter shaft 26 lies slightly below the plan established by the carriage shaft 22 and motor shaft 30. This establishes that tension on the belt 32 helps to hold the forward edge of the carriage 21 downwardly so that the stylus 18 cooperates with the master key 12 and the cutter l9 cooperates with the key blank 13. Additionally, the direction of rotation of the cutter 19 is clockwise as shown in FIG. 2 and this means that rotation of the belt 32 is downwardly over the outer edge of the belt pulley 27 on the cutter shaft 26. This also aids in holding the stylus 18 down against the master key 12.

A fixed shaft 76 is fixed on the base 14 approximately directly below the cutter shaft 22. This fixed shaft has a relieved portion 77 where a part of the circumference of the shaft is cut away. Smooth entrance and exit ramps are prov ided on each end of the relieved portion in order to smoothly merge with the circumference of this shaft 76. The relieved portion extends for a distance slightly less than the distance of travel of a carriage 21, and does not quite extend to the initial position of the carriage 21 of FIG. 1. A depending boss 78 is fixed on the downward edge of the carriage 21 and carries an adjusting screw 79. The inner end of this screw 79 cooperates with either the circumference of the fixed shaft 76, or the relieved portion 77, depending upon the position of the carriage 21. When the carriage 21 is in the initial position as shown in HO. 1, then the adjusting screw 79 is in engagement with the unrelieved circumference of this fixed shaft 76. After the carriage 21 is moved about one-eighth of an inch to the left, the adjusting screw 79 cooperates with the relieved portion 77 and this allows the carriage 21 to drop downwardly about oneeighth of an inch. At this time when the stylus 18 may cooperate to the full depth with the valleys on the master key 12. The reason for holding this carriage 21 upwardly about one-eighth of an inch when it it is at the initial position of FIG. 1, is so that the stylus l8, and the cutter 19, may pass over and not touch a longitudinal gauge surface 80 on the vises 16 and 17. Such longitudinal gauge surfaces are necessary to engage the tip end of the keys 12 and 13 for certain types of keys. This assures the proper longitudinal positioning of these keys relative to the stylus 18 and cutter 19.

The above description and drawing disclose a key cutting machine which is well adapted for semi-automatic operation by relatively unskilled personnel and by many different people, so that just one person alone need not be the operator of the machine. The machine is rugged and does not get out of adjustment easily, therefore, also helping to permit operation by a number of different people. The door 61 is closed when the machine is in operation and this makes the machine safe for operation out near the public because they cannot be injured by the moving parts of the machine since the machine will stop the cutter 19 when the door 61 is raised. All one needs to do is clamp the master key 12 and the blank key 13 in the vises, close the door and turn on the machine and it will automatically cut a key in accordance with the master key 12. The first drive means is a yielding drive means which achieves safety in the longitudinal reciprocation of the carriage 21 in the cutting direction. Should any unforeseen obstacles be placed in the way of carriage 21, either through the instrumentality of the stylus 18 or cutter 19 or any other obstacle. the springs 39 will extend and the carriage 21 will not continue its cutting movement until the obstacle is overcome. If it is merely some difficult place to cut on the key blank 13, the springs 39 may extend slightly but later the carriage 21 may catch up to have the cam again contacting the cam follower 38. This is a safety factor to avoid damage to the machine or also to avoid injury to personnel. The brush mechanism 45 comes into play only during the return movement of the carriage 21 to move any burr on the cut key 13 so that the key is ready for any use without further hand deburring operations. At the end of the cutting operation, the door 61 may be raised, the manual handles 23 raised and the master key 12 and cut key removed from the machine. The machine is then ready for the next keycutting cycle of operation.

The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrange ment of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. A key cutting machine, comprising in combination,

a base,

a master key vise,

a blank key vise,

a stylus to cooperate with a master key in the master key vise,

a key cutter to cut a blank key in the blank key vise,

a carriage movable on said base,

means including said carriage establishing relative longitudinal and lateral movement between said key cutter and blank key vise in accordance with relative longitudinal and lateral movement, respectively, between said stylus and master key vise,

motor means,

first yielding drive means from said motor means to said carriage for said relative longitudinal movement in a first direction,

and second positive drive means from said motor means to said carriage for said relative longitudinal movement in the opposite direction.

2. A key cutting machine as set forth in claim 1, including cam means as a part of said first and second drive means.

3. A key cutting machine as set forth in claim 1, including cam follower means cooperable with said cam means and included in said first and second drive means.

4. A key cutting machine as set forth in claim 2, including first and second carn followers cooperable with said cam means and included in said first and second drive means, respectively.

5. A key cutting machine as set forth in claim 4, including spring means acting on said first cam follower to establish said first yielding drive means.

6. A key cutting machine as set forth in claim 2, including cam follower means cooperable with said cam means,

and spring means acting between said cam means and said cam follower means to establish said first drive means as a yielding means.

7. A key cutting machine as set forth in claim 4, including means mounting said cam means for rotation on said carriage,

means mounting said second cam follower means longitudinally fixed relative to said base,

means mounting said first cam follower longitudinally movable relative to said base and acting on said cam means at a location generally opposite said second cam follower,

and spring means acting between said cam followers.

8. A key cutting machine as set forth in claim 1, including brush means selectively operable with a key in said key vise in accordance with said first and second drive means.

9. A key cutting machine as set forth in claim 8, including means rendering said brush means operable with the second drive means and inoperable with said first drive means.

l0. A key cutting machine as set forth in claim 8, including means to reciprocate said brush in a path transverse to a burr on any out key in said blank key vise.

11. A key cutting machine as set forth in claim 8, including means to establish said brush in contact with a key in said blank key vise substantially at the transfer of drive from said first to said second drive means.

12. A key cutting machine as set forth in claim 9, including a door on said key cutting machine,

said door being closable on said machine to protect personnel during key cutting operations,

and means to recock said brush operating mechanism for actuation with said second drive means in accordance with retraction of said door.

13. A keycutter as set forth in claim 1, including a brush to debur the cut key blank during the return movement of said carriage,

first and second arms interconnected at an arm pivot,

a carriage shaft pivotally journalling said carriage,

said first arm pivotally journalled on said carriage shaft and connected for longitudinal reciprocation thereon with said carriage,

a tension spring fastened on said first and second arms urging said arms into a straight condition with said brush mounted on said second arm,

a longitudinal groove in said carriage shaft having an exit ramp to the circumference of said shafl,

an elastic finger on said first brush arm circumferentially positioned on said first brush arm to have the tip of said plunger enter said carriage shaft groove when said carriage is raised into a disengaged position of the cutter relative to the key blank,

the subsequent lowering of the carriage toward operative position of the carriage bending the second arm relative to the first arm to form a knee at the arm pivot and to establish the brush in a retracted position out of engagement with the key blank during the cutting direction of movement of the carriage,

the completion of cutting movement of the carriage causing said elastic finger to ride up said exit ramp out of said groove onto said carriage shaft circumference whereupon said arm tension spring straightens out said first and second brush arms to cause said brush to move to an extended position into engagement with the cut key,

an eccentric cam mounted for rotation, and

a cam follower on the outer end of said second brush arm cooperating with said eccentric cam to cause up and down arcuate movement of said brush transverse to and in engagement with said out key during the return movement of said carriage to thus break off any burr on said cut key.

14. A key cutting machine as set forth in claim 1, including means mounting said key cutter for rotation on said carriage,

means mounting said motor means on said base to drive said rotatable key cutter,

a flexible belt interconnecting pulleys on said motor means and rotatable cutter,

said carriage being movable about a pivot shaft to permit lateral movement of said cutter. I I 15. A key cutting machine as set forth in claim 14, including the pivot axis of said carriage being parallel to and between the axis of said motor means and the axis of said rotatable cutter,

and the axis of said rotatable cutter lying below a plane established by the motor means axis and the carriage pivot axis to establish downward pull of said rotatable cutter toward the blank key vise by tension in said belt.

16. A key cutting machine as set forth in claim 15, including a belt tension pin mounted on said carriage,

said carriage being pivotally raisable to an inoperable posi tion for key changing,

and said belt tension pin engaging said belt to maintain tension thereon as said carriage is raised.

17. A key cutting machine as set forth in claim 15, including establishing rotation of said belt in a downward direction on the outer edge of the pulley on said key cutter shaft to urge said carriage downwardly.

18. A key cutting machine as set forth in claim 1, including a movable door on said key cutting machine,

and means connecting said door to move said carriage.

19. A key cutting machine as set forth in claim 18, including releasable means interconnecting said door and said carriage to permit the carriage to be moved downwardly independently of the door.

20. A key cutting machine as set forth in claim 18, including means connecting said door movement to control said key cutter.

21. A key cutting machine as set forth in claim 18, including switch means controlled by opening of said door to stop rotation of said key cutter.

22. A key cutting machine as set forth in claim 21 including means to continue operation of said first and second drive means despite stopping of said key cutter.

23. A key cutting machine as set forth in claim 22, including a drive motor in said motor means separate from a key cutter motor,

and said drive motor continuing operation of said drive means.

l l l l lOlO44 (H07 

1. A key cutting machine, comprising in combination, a base, a master key vise, a blank key vise, a stylus to cooperate with a master key in the master key vise, a key cutter to cut a blank key in the blank key vise, a carriage movable on said base, means including said carriage establishing relative longitudinal and lateral movement between said key cutter and blank key vise in accordance with relative longitudinal and lateral movement, respectively, between said stylus and master key vise, motor means, first yielding drive means from said motor means to said carriage for said relative longitudinal movement in a first direction, and second positive drive means from said motor means to said carriage for said relative longitudinal movement in the opposite direction.
 2. A key cutting machine as set forth in claim 1, including cam means as a part of said first and second drive means.
 3. A key cutting machine as set forth in claim 1, including cam follower means cooperable with said cam means and included in said first and second drive means.
 4. A key cutting machine as set forth in claim 2, including first and second cam followers cooperable with said cam means and included in said first and second drive means, respectively.
 5. A key cutting machine as set forth in claim 4, including spring means acting on said first cam follower to establish said first yielding drive means.
 6. A key cutting machine as set forth in claim 2, including cam follower means cooperable with said cam means, and spring means acting between said cam means and said cam follower means to establish said first drive means as a yielding means.
 7. A key cutting machine as set forth in claim 4, including means mounting said cam means for rotation on said carriage, means mounting said second cam follower means longitudinally fixed relative to said base, means mounting said first cam follower longitudinally movable relative to said base and acting on said cam means at a location generally opposite said second cam follower, and spring means acting between said cam followers.
 8. A key cutting machine as set forth in claim 1, including brush means selectively operable with a key in said key vise in accordance with said first and second drive means.
 9. A key cutting machine as set forth in claim 8, including means rendering said brush means operable with the second drive means and inoperable with said first drive means.
 10. A key cutting machine as set forth in claim 8, including means to reciprocate said brush in a path transverse to a burr on any cut key in said blank key vise.
 11. A key cutting machine as set forth in claim 8, including means to establish said brush in contact with a key in said blank key vise substantially at the transfer of drive from said first to said second drive means.
 12. A key cutting machine as set forth in claim 9, including a door on said key cutting machine, said door being closable on said machine to protect personnel during key cutting operations, and means to recock said brush operating mechanism for actuation with said second drive means in accordance with retraction of said door.
 13. A keycutter as set forth in claim 1, including a brush to debur the cut key blank during the return movement of said carriage, first and second arms interconnected at an arm pivot, a carriage shaft pivotally journalling said carriage, said first arm pivotally journalled on said carriage shaft and connected for longitudinal reciprocation thereon with said carriage, a tension spring fastened on said first and second arms urging said arms into a straight condition with said brush mounted on said second arm, a longitudinal groove in said caRriage shaft having an exit ramp to the circumference of said shaft, an elastic finger on said first brush arm circumferentially positioned on said first brush arm to have the tip of said plunger enter said carriage shaft groove when said carriage is raised into a disengaged position of the cutter relative to the key blank, the subsequent lowering of the carriage toward operative position of the carriage bending the second arm relative to the first arm to form a knee at the arm pivot and to establish the brush in a retracted position out of engagement with the key blank during the cutting direction of movement of the carriage, the completion of cutting movement of the carriage causing said elastic finger to ride up said exit ramp out of said groove onto said carriage shaft circumference whereupon said arm tension spring straightens out said first and second brush arms to cause said brush to move to an extended position into engagement with the cut key, an eccentric cam mounted for rotation, and a cam follower on the outer end of said second brush arm cooperating with said eccentric cam to cause up and down arcuate movement of said brush transverse to and in engagement with said cut key during the return movement of said carriage to thus break off any burr on said cut key.
 14. A key cutting machine as set forth in claim 1, including means mounting said key cutter for rotation on said carriage, means mounting said motor means on said base to drive said rotatable key cutter, a flexible belt interconnecting pulleys on said motor means and rotatable cutter, said carriage being movable about a pivot shaft to permit lateral movement of said cutter.
 15. A key cutting machine as set forth in claim 14, including the pivot axis of said carriage being parallel to and between the axis of said motor means and the axis of said rotatable cutter, and the axis of said rotatable cutter lying below a plane established by the motor means axis and the carriage pivot axis to establish downward pull of said rotatable cutter toward the blank key vise by tension in said belt.
 16. A key cutting machine as set forth in claim 15, including a belt tension pin mounted on said carriage, said carriage being pivotally raisable to an inoperable position for key changing, and said belt tension pin engaging said belt to maintain tension thereon as said carriage is raised.
 17. A key cutting machine as set forth in claim 15, including establishing rotation of said belt in a downward direction on the outer edge of the pulley on said key cutter shaft to urge said carriage downwardly.
 18. A key cutting machine as set forth in claim 1, including a movable door on said key cutting machine, and means connecting said door to move said carriage.
 19. A key cutting machine as set forth in claim 18, including releasable means interconnecting said door and said carriage to permit the carriage to be moved downwardly independently of the door.
 20. A key cutting machine as set forth in claim 18, including means connecting said door movement to control said key cutter.
 21. A key cutting machine as set forth in claim 18, including switch means controlled by opening of said door to stop rotation of said key cutter.
 22. A key cutting machine as set forth in claim 21 including means to continue operation of said first and second drive means despite stopping of said key cutter.
 23. A key cutting machine as set forth in claim 22, including a drive motor in said motor means separate from a key cutter motor, and said drive motor continuing operation of said drive means. 